refactor(login): remove loading instance from login methods for cleaner code

- Eliminated unnecessary loading instance creation in the login, SMS login, and mobile binding methods to streamline the code.
- Retained message handling for user feedback upon successful operations.

src/views/User/login.vue

@@ -97,7 +97,7 @@
 </template>
 <script>
     import Vue from 'vue';
-    import { Loading, Message } from 'element-ui';
+    import { Message } from 'element-ui';
     import Util from "../../tool";
 
     Vue.prototype.$message = Message
@@ -379,17 +379,12 @@
                     return false;
                 }
 
-                let loadingInstance = Loading.service({
-                    background: 'rgba(0, 0, 0, 0)'
-                });
-
                 this.$http('post', "/auth/login", {
                     mobile: this.form.mobile,
                     password: this.form.password,
                     captcha: this.form.captcha,
                     captcha_key: this.form.captcha_key
                 }).then(res => {
-                    loadingInstance.close();
                     if (res.code === 0) {
                         sessionStorage.removeItem('tabs');
                         localStorage.removeItem('supplier_id');
@@ -452,15 +447,10 @@
                     return false;
                 }
 
-                var loadingInstance = Loading.service({
-                    background: 'rgba(0, 0, 0, 0)'
-                });
-
                 this.$http('post', "/auth/smsLogin", {
                     mobile: this.smsForm.mobile,
                     sms_code: this.smsForm.smsCode
                 }).then(res => {
-                    loadingInstance.close();
                     if (res.code === 0) {
                         sessionStorage.removeItem('tabs');
                         localStorage.removeItem('supplier_id');
@@ -517,15 +507,10 @@
                     return false;
                 }
 
-                var loadingInstance = Loading.service({
-                    background: 'rgba(0, 0, 0, 0)'
-                });
-
                 this.$http('post', "/api/user/bindMobile", {
                     mobile: this.bindForm.mobile,
                     sms_code: this.bindForm.smsCode
                 }).then(res => {
-                    loadingInstance.close();
                     if (res.code === 0) {
                         this.$message({
                             message: '绑定成功',